Toyota Tacoma (2015-2018) Service Manual: Diagnosis System
DIAGNOSIS SYSTEM
1. DESCRIPTION
The 4 wheel drive control ECU records DTCs when the ECU detects a malfunction in the ECU itself or in system circuits.
The DTCs can be read through the DLC3 of the vehicle. When the system seems to be malfunctioning, use the Techstream to check for malfunctions and perform troubleshooting.
2. CHECK DLC3
(a) Inspect the battery voltage.
Standard voltage:
11 to 14 V
If the voltage is below 11 V, recharge the battery before proceeding.
(b) Check the DLC3 (See page .gif)
).
3. FUNCTION OF INDICATOR LIGHT
(a) When a problem occurs in the touch select 2-4 and high-low system, a message is displayed on the multi-information display and/or the 4LO indicator light on the combination meter assembly rapidly blinks* to inform the driver of the problem.
- *: 0.25 second intervals (0.25 seconds on and 0.25 seconds off)
(b) Indicator light status (illumination and blinking) or multi-information display status when DTC is output.
TOUCH SELECT 2-4 AND HIGH-LOW SYSTEM|
DTC No. |
4WD Indicator Light (Green) |
4LO Indicator Light |
Multi-information Display Message |
|---|---|---|---|
|
U0100 |
When 2WD: Not illuminated When H4 or L4: Illuminated |
Rapidly blinking |
- |
|
U0122 |
Not illuminated |
Rapidly blinking*1 |
2WD-4WD mode change malfunction visit your dealer |
|
U0416 |
|||
|
P163B |
|||
|
P17A0 |
|||
|
P17A4 |
Not illuminated |
Not illuminated |
2WD-4WD mode change malfunction visit your dealer |
|
P17A8 |
Not illuminated |
Rapidly blinking |
2WD-4WD mode change malfunction visit your dealer |
|
P17A9 |
|||
|
P17AA |
|||
|
P17AC |
|||
|
P17C7 |
Not illuminated |
When 2WD or H4: Not illuminated When L4: Illuminated |
2WD-4WD mode change malfunction visit your dealer |
|
P17C8 |
|||
|
P2772 |
When 2WD: Not illuminated When H4 or L4: Illuminated |
Rapidly blinking |
- |
|
P279E |
Not illuminated |
Rapidly blinking |
2WD-4WD mode change malfunction visit your dealer |
Rapidly blinking: Blinks at 0.25 second intervals (0.25 seconds on and 0.25 seconds off)
- *1: P163B may also display the 2WD/4WD mode status.
System Diagram
SYSTEM DIAGRAM
Transmitting ECU (Transmitter)
Receiving ECU
Signal
Communication Method
4 wheel drive control ECU
Skid ...
Dtc Check / Clear
DTC CHECK / CLEAR
1. CHECK DTC
(a) Check the DTCs.
(1) Turn the ignition switch off.
(2) Connect the Techstream to the DLC3.
(3) Turn the ignition switch to ON.
(4) Turn the Techstream on.
(5) ...
Other materials:
Accumulator Low Pressure (C1256)
DESCRIPTION
The accumulator pressure sensor is connected to the skid control ECU in the master
cylinder solenoid.
DTC No.
DTC Detecting Condition
Trouble Areas
C1256
Fluid pressure inside the accumulator drops below the specification ...
Problem Symptoms Table
PROBLEM SYMPTOMS TABLE
HINT:
Use the table below to help determine the cause of problem symptoms.
If multiple suspected areas are listed, the potential causes of the symptoms
are listed in order of probability in the "Suspected Area" column of the
table. Check each sy ...
On-vehicle Inspection
ON-VEHICLE INSPECTION
CAUTION / NOTICE / HINT
HINT:
Perform "Inspection After Repair" after replacing an ignition coil assembly or
spark plug (See page ).
PROCEDURE
1. PERFORM SPARK TEST
(a) Check for DTCs (See page ).
NOTICE:
If any DTC is output, perform the troubleshooting p ...
